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♦       ILLINOIS  STATE  t 

|        LABORATORY  1 

|    OF  NATURAL  HISTORY  1 

LIBRARY  I 


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OF  THE 

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Of    ILLINOIS 

?URAL   HISTORY    SURVE^ 

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Field  Columbian  Museum. 

Publication  122. 

Geological  Series.  Vol.  Ill,  No.  6. 


METEORITE   STUDIES    II 


Oliver  Cummings  Farrington, 
Curator,  Department  of  Geology. 


Chicago,  U.  S.  A. 

October   1,   1907. 


METEORITE  STUDIES   II 

BY 

OLIVER  CUMMINGS  FARRINGTON. 


BATH  FURNACE. 

Of  the  three  known  stones  of  this  fall,  one-half  the  smallest  one, 
weighing  223  grams,  came  into  the  possession  of  the  Museum  (Mus. 
No.  Me  570).  This  individual  is  of  irregular  disk-like  form,  of 
*XA  x  i}£  x  %  inches  dimension.  A  side  and  front  view  of  it  are 
shown  in  Plate  XXIX.  Though  its  shape  indicates  that  it  was  a  scal- 
ing, it  was  completely  encrusted  and  shows  orientation.  One  of  the 
broad  surfaces  was  plainly  the  front  side,  the  opposite  the  rear  side. 
The  front  side  shows  lines  of  flow  radiating  from  an  eccentric  point. 
These  lines  have  under  the  lens  the  form  of  ridges  of  inverted  V  shape 
gradually  branching  and  tapering  out.  These  ridges  are  of  shining 
black  glass  and  rise  above  a  dull-black  ground.  The  interior  sub- 
stance of  the  meteorite  is  gray  with  rusted  spots  about  the  metallic 
grains.  It  is  of  sufficiently  firm  texture  to  take  a  good  polish.  Under 
the  microscope  the  crust  is  seen  to  be  relatively  thin,  .2  -  .3  mm.  The 
zones  of  Tschermak  are  indicated,  but  are  by  no  means  well  marked. 
For  the  most  part  the  crust  appears  as  a  black,  opaque  aggregate  bor- 
dering the  edge  of  the  section,  with  here  and  there  transparent  grains 
of  various  sizes  seen  in  polarized  light  to  be  unaltered  olivine.  The  re- 
mainder of  the  section  appears  in  ordinary  light  a  confused  mass  of 
transparent  grains  considerably  iron  stained  and  interspersed  with 
metallic  grains  of  very  irregular  but  usually  elongated  shapes.  Among 
these  troilite  is  more  numerous  than  nickel -iron.  An  opaque,  black 
substance  also  occurs  in  small  quantity  connected  here  and  there  with 
the  metallic  grains.  It  may  be  of  ferrous  or  carbonaceous  nature. 
Chondri  are  but  occasionally  and  imperfectly  outlined.  In  polarized 
light  the  chondri  can  be  more  readily  recognized.  They  are  not  nu- 
merous, however,  the  greater  part  of  the  section  being  made  up  of  an- 
hedral  grains  of  various  sizes.  Chondri  where  visible  are  for  the  most 
part  sharply  outlined  from  the  surrounding  mass.  Those  composed 
of  alternate  lamellae  of  olivine  and  glass  are  the  most  common  and 
next  in  number  are  those  composed  chiefly  of  fibrous  enstatite.     Large 


ii2  Field  Columbian  Museum  —  Geology,  Vol.  III. 

chondri  composed  of  porphyritic  anhedral  olivines  or  of  olivine  and 
enstatite  also  occur.  These  olivines  frequently  reach  a  length  of 
.2  -  .3  mm.  and  have  well-defined  prismatic  outlines.  The  interstices 
between  the  crystals  are  usually  filled  with  a  turbid  glass.  The  out- 
lines of  these  chondri  as  a  rule  are  less  well-marked  than  are  those 
composed  of  olivine  and  glass.  Most  of  the  chondri  have  spheroidal 
outlines,  though  a  few  fragmental  forms  occur.  Among  the  constitu- 
ents of  the  general  mass,  lath-shaped  crystals  of  enstatite  .3  -  .5  mm. 
in  length,  with  cleavage  parallel  to  the  direction  of  length  are  the  most 
conspicuous.  These  and  the  enstatite  chondri  are  sufficiently  numer- 
ous to  indicate  a  large  proportion  of  this  mineral  in  the  constitution  of 
the  mass.  Besides  enstatite,  grains  of  olivine  of  various  sizes  and 
outlines  are  to  be  seen  in  considerable  quantity. 

Plate  XXX,  from  a  photograph  made  by  the  writer  about  six 
months  after  the  fall,  shows  the  place  of  fall  of  the  178  lb.  mass.  The 
point  was  the  base  of  the  tree  in  the  foreground.  The  meteorite  in 
falling  grazed  the  tree  at  the  right,  leaving  a  scar  the  observation  of 
which  by  a  squirrel  hunter  led  to  the  discovery  of  the  mass.  Erection 
of  a  pole  connecting  the  scar  and  the  place  of  fall  of  the  meteorite 
seemed  to  the  writer  to  indicate  a  nearly  vertical  direction  of  fall. 
Miller,*  however,  estimated  the  angle  to  be  770  with  the  horizon,  or 
130  from  vertical.  The  large  roots  of  the  tree  prevented  the  stone 
from  going  deeply  into  the  soil,  and  it  was  found  resting  on  them. 
Considering  the  weight  of  the  mass  and  the  distance  of  its  fall  it  is  re- 
markable that  it  was  not  shattered  by  the  impact  and  that  the  roots 
on  which  it  fell  were  not  more  deeply  bruised. 

CHUPADEROS. 

The  two  known  masses  of  this  meteorite  were  found,  as  was  stated 
at  an  early  period,  lying  only  about  800  feet  apart.  This  proximity 
and  the  jagged  surface  to  be  found  on  each  renders  it  very  probable, 
as  was  suggested  by  Daubree,f  if  not  earlier  by  others,  that  the  two 
pieces  once  constituted  a  single  mass  which  was  torn  apart  during  its 
tall  to  the  earth.  The  probable  dimensions  of  this  mass  were  given 
by  Daubree  as  follows:  Length  4.65  m.  (16  feet),  width  1.50  m.  (5 
feet)  and  thickness  0.45  m.  (22  inches).  The  dimensions  thus  ob- 
fained  by  Daubree  were  evidently  arrived  at  by  assuming  a  joining  of 
the  two  masses  end  to  end.  Such  a  joining,  however,  would  not  place 
the  torn  surfaces  together.     In  order  to  determine  what  the  form  and 

*  Science,  1903.     N.  S.  Vol.  XVIII,  p.  244. 
t  Comptes  Rendus,  1889,  Vol.  CIX,  p.  726. 


Oct.,  1907.      Meteorite  Studies  II  —  Farrington.  113 

dimensions  of  the  mass  would  have  been  if  the  two  parts  were  joined 
along  the  fractured  surfaces,  the  two  full-sized  models  of  these  masses 
in  possession  of  the  Museum  were  joined  in  this  way.  The  resulting 
form  is  shown  in  the  accompanying  plate.  (Plate  XXXI.)  It  is  seen 
to  be  broad  and  tabular  with  irregular  outline.  Along  the  line  where 
disruption  took  place  there  was  an  evident  constriction.  The  corre- 
spondence between  the  broken  surfaces  is  such  as  to  leave  little 
doubt  that  they  were  once  joined.  The  dimensions  of  the  mass  so 
formed  are:  Length  12  feet  (3.6  meters)  and  width  7  feet  (2.1 
meters).  The  weight  of  this  mass  would  have  totaled  about  21  tons 
(20,881  kgs.).  It  would  be  of  interest  to  know  which  surfaces  of  the 
two  masses  lay  uppermost  when  found,  but  no  record  seems  to  have 
been  made  of  this  point.  There  is  a  marked  difference  in  the  pittings 
on  the  two  broad  surfaces  and  they  correspond  on  the  two  masses 
when  joined.  Thus  pittings  on  the  side  shown  in  the  accompanying 
plate  are  deeper  and  narrower  than  those  on  the  opposite  side.  The 
indications  are  therefore  that  the  side  shown  in  the  accompanying 
plate  was  the  front  side  in  falling. 

As  the  writer  is  not  aware  that  any  photographs  of  the  two  original 
masses  have  ever  been  published,  the  accompanying  cuts  (Plates 
XXXII-XXXIII)  from  photographs  made  by  him  in  1896  are  pre- 
sented. These  show  the  masses  as  they  are  installed  in  the  National 
School  of  Mines  in  the  City  of  Mexico.  With  them,  as  installed,  are 
placed  the  Concepcion  (Adargas)  and  Zacatecas  meteorites.  The 
large  Chupaderos  and  the  Concepcion  masses  are  installed  at  one  side 
of  the  entrance  of  the  School  of  Mines  (Plate  XXXII)  and  the  smaller 
Chupaderos  and  the  Zacatecas  masses  at  the  other  side  of  the  entrance 
(Plate  XXXIII).  In  Plate  XXXIV  is  shown  the  Morito  (San 
Gregorio)  mass  which  is  likewise  installed  at  the  School  of  Mines,  and 
of  which  a  photograph  was  made  by  the  writer  at  the  same  time. 
This  is  a  beautifully  oriented  meteorite  and,  as  will  be  seen,  has  been 
mounted  in  the  position  it  assumed  when  falling. 

IRON  CREEK. 

A  cast  of  this  meteorite  recently  received  by  the  Museum  (Museum 
No.  Me  763)  through  the  kindness  of  the  Geological  Survey  of  Canada 
affords  an  opportunity  for  the  study  of  some  features  which  have  not 
previously  received  description.  The  meteorite  is  remarkable  for 
its  orientation,  the  characters  of  front  and  rear  sides  being  shown  very 
plainly.  In  perfection  of  form  in  this  respect  it  equals  the  Cabin 
Creek  meteorite,  which  in  general  shape  it  resembles.     In  previous  de- 


ii4  Field  Columbian  Museum  —  Geology,  Vol.  111. 

scriptions  of  this  meteorite*  it  has  merely  been  stated  that  the  mass 
was  "irregularly  triangular  and  much  broader  than  thick" — and  no 
dimensions  have  been  given. 

The  form  of  the  Iron  Creek  meteorite,  as  seen  from  its  cast,  is  that 
of  a  low  cone,  8}4  inches  (22  cm.)  high  and  22  inches  (56  cm.)  in  diam- 
eter. The  outline  of  the  base  of  the  cone  is  an  incomplete  circle,  an 
approximately  straight  contour  cutting  off  one  side  so  that  only  about 
three-fourths  of  the  circle  is  present.  The  width  of  the  mass  in  this 
direction  is  17  inches  (43  cm.)  Were  the  circle  complete  the  apex  of 
the  cone  would  occupy  a  position  near  its  center,  but  with  the  mass 
shaped  as  it  is  the  apex  is  situated  close  to  the  straight  side.  At  one 
point  where  the  straight  side  joins  the  circular  outline  there  was  evi- 
dently, in  the  original  mass,  a  prolongation  perhaps  a  few  inches  in 
length,  which  having  formed  the  most  convenient  part  of  the  meteor- 
ite for  removal  has  been  sawed  off  for  purposes,  doubtless,  of  analysis 
and  distribution.  While  the  form  of  the  meteorite  as  a  whole  is  coni- 
cal, it  is  also  arched,  the  base  being  concave  and  the  sides  convex. 
The  greatest  depth  of  the  concavity  of  the  base  is  about  one  and  a  half 
inches  and  occurs  opposite  the  •  apex.  This  general  concavity  is 
also  subdivided  by  two  secondary  concave  areas,  one  about  seven 
inches  (18  cm.),  the  other  about  ten  inches  (25  cm.)  in  diameter. 
These  are  again  subdivided  by  broad,  shallow  pits  from  two  to  four 
inches  in  diameter.  The  perimetral  edge  formed  by  the  meeting  of 
the  sides  and  base  is  irregular  in  contour  and  from  one  to  two  inches 
in  thickness.  The  broad,  shallow  pits  of  the  base,  which  by  their 
form  characterize  this  as  the  rear  side  of  the  meteorite  are,  as  has 
been  stated,  from  two  to  four  inches  (5-10  cm.)  in  diameter.  Their 
form  is  approximately  circular  although  they  at  times  tend  to  be  oval 
or  polygonal.  The  ridges  between  the  pits  are  low,  rounded  and 
merge  into  the  pits.  The  pits  of  the  convex  surface  of  the  meteorite 
present  considerable  contrast  to  these.  They  are  smaller,  rarely  ex- 
ceeding two  inches  (5  cm.)  in  diameter,  are  deeper  in  proportion  to 
their  diameters,  more  irregular  in  shape  and  the  ridges  between  them 
are  higher.  They  lack  uniformity  of  shape  or  arrangement.  Some  are 
long  and  narrow,  others  three-sided,  others  again  more  nearly  circular. 
The  apex  of  the  cone  appears  to  have  been  less  oxidized  than  the  rest  of 
the  mass,  indicating  that  the  crust  had  sprayed  off  at  this  point. 
It  presents  a  smooth  surface  about  two  inches  (5  cm.)  in  diameter, 
convex  except  for  a  small,  saucer -like  depression  about  yi  inch  (1  cm:) 
in  diameter  in  its  center.  The  base  and  the  sides  of  the  cone  meet  in  a 
sloping  edge  except  on  the  side  already  described  as  approximately 
♦1887  Proc.  Trans.  Roy.  Soc.  Canada,  Vol.  IV.  p.  97. 


Oct.,   1907.       Meterorite  Studies  II  —  Farrington.  115 

straight.  Here  a  broad  flat  surface  is  presented,  perpendicular  to 
the  base  of  the  cone  or  as  if  a  section  had  been  cut  through  the  cone 
at  one  side  of  the  apex  and  removed.  The  pittings  of  this  surface 
resemble  furrows  and  run  in  general,  parallel  to  the  axis  of  the  cone. 
Some,  however,  converge  from  points  on  the  side  toward  the  central 
point  of  the  base.  This  is  the  course  which  currents  of  air  rushing 
from  the  front  side  backward  to  the  partial  vacuum  behind  might  be 
expected  to  take.  The  characters  above  described  make  it  clear  that 
the  convex  surface  with  its  deeper,  smaller  pits  was  the  front  side  of 
the  meteorite  in  falling.  The  characters  of  the  crust  cannot  be  deter- 
mined from  the  cast  nor  are  minute  drift  phenomena,  if  any  occur,  to 
be  seen.  Brezina,  however,  states*  that  the  rear  side  has  a  bark  crust 
0.5  to  1  mm.  thick.  The  plate  accompanying  the  present  paper 
(Plate  XXXV)  shows  the  characters  above  described.  The  adoption 
by  the  writer  for  this  meteorite  of  the  name  Iron  Creek  instead  of  the 
more  usual  one  of  Victoria  is  on  account  of  information  received  from 
Mr.  Johnston  of  the  Geological  Survey  that  the  small  mission  station 
of  Victoria,  from  which  the  meteorite  received  that  name,  is  one  hun- 
dred and  fifty  miles  from  the  locality  where  the  meteorite  was  found, 
and  it  is  no  longer  known  by  that  name,  its  present  name  being 
Papan.  Iron  Creek  is  a  well-defined  stream  only  twenty-five  miles  in 
length,  which  takes  its  name  from  the  fact  that  the  meteorite  was 
found  near  it.  Iron  Creek,  moreover ;  is  the  English  translation  of  the 
Indian  name  given  to  the  stream  before  the  white  man  entered  the 
country.  The  meteorite  was  known  to  the  Indians  and  held  in  great 
veneration  by  them. 

LAMPA,  CHILE. 

Among  a  number  of  meteorites  obtained  by  the  late  Professor  Henry 
A.  Ward  in  Chile  in  1905  one  was  placed  by  Professor  Ward  in  the 
hands  of  the  writer  for  description.  The  only  information  given  the 
writer  by  Professor  Ward  at  that  time  was  that  the  meteorite  had  been 
handed  to  him  by  some  one  at  the  School  of  Mines  at  Santiago.  On 
corresponding  with  the  School  of  Mines,  the  Director,  Senor  A.  Orrego 
Cortes,  kindly  informed  the  writer  that  the  meteorite  had  been  found 
in  the  Sierra  de  Chicauma  near  Lampa.  The  latitude  of  the  locality 
is  33°  lS'  S.  and  the  longitude  710  W.  The  height  above  the  sea  level 
is  1000  metres.  Sehor  Cortes  also  stated  that  other  specimens  of  the 
find  aggregating  5-6  kilograms  in  weight  had  been  preserved. 

The  meteorite  is  of  the  stony  variety.     From  the  locality  it  would 
seem  to  be  a  different  fall  from  any  yet  described.     The  material  pro- 
*  Wiener  Sammlung,  1895,  p.  279. 


n6         Field  Columbian  Museum  —  Geology,  Vol.  III. 

cured  by  Professor  Ward  was  a  single  individual  about  10  x  15  cm. 
in  size.  When  received  by  the  writer,  however,  the  mass  had  been 
broken  in  two  parts.  The  smaller  of  these  parts  had  been  sawed  in 
two,  and  one  surface  of  one  polished,  while  the  other  part  was  missing 
altogether.  It  is  impossible,  therefore,  to  state  what  the  exact  orig- 
inal form  and  weight  of  the  mass  was,  but  it  is  not  probable  that  the 
missing  part  exceeded  one  pound  (453  grams)  in  weight.  The  total 
weight  of  the  parts  in  hand  amounted  to  6%  pounds  (2.8  kgs.).  Con- 
tinuation of  the  contours  of  the  two  portions  in  hand  gives  a  pretty  ac- 
curate idea  of  the  original  form,  the  space  probably  occupied  by  the 
missing  portion  being  indicated  in  Plate  XXXVI.  The  original 
form  of  the  mass  was  evidently  that  of  a  short  cylinder  about  six  inches 
(15  cm.)  in  diameter  and  four  inches  (10  cm.)  in  height.  The  surface 
of  one  end  of  the  cylinder  tends  to  be  convex  and  that  of  the  other 
concave.  These  differences  of  curvature  together  with  distinctions 
in  crust  and  pittings  show  pretty  conclusively  that  one  was  the  front 
and  the  other  the  rear  side  of  the  meteorite  in  falling.  On  the  front 
and  rear  surfaces  of  the  meteorite  the  primary  crust  is  pretty  uni- 
formly present.  On  the  sides,  however,  it  appears  only  at  intervals, 
indicating  that  during  the  fall  of  the  meteorite  to  the  earth,  or  since 
its  arrival,  portions  have  been  broken  off.  How  much  has  been  sepa- 
rated in  this  way  it  is  obviously  impossible  to  determine,  but  it  is  quite 
probable  that  at  one  time  the  mass  had  a  more  disk-like  shape  than  at 
present.  The  surface  of  the  front  side  of  the  meteorite  is  very  smooth 
and  varnish -like.  There  are  no  well-marked  pits  to  be  seen, the  near- 
est approach  to  them  being  three  or  four  shallow,  irregular  depressions 
about  one  inch  (2.5  cm.)  in  diameter.  The  color  of  this  surface  is  in 
general  a  dull  hematite-red,  shading  to  darker  about  the  edges  of  the 
meteorite.  The  smoothness  and  color  give  an  appearance  much  as  if 
the  surface  had  been  coated  with  a  red  varnish.  The  most  remarkable 
feature  of  this  front  surface  is  a  system  of  cracks  or  fissures  which  trans- 
verse it.  These  cracks  appear  to  be  quite  independent  of  the  contour 
of  the  surface.  In  general  they  may  be  said  to  mark  triangular  areas, 
the  sides  of  the  triangles  being  about  two  inches  (5  cm.)  in  length. 
In  width  the  fissures  vary,  but  rarely  exceed  one  millimeter.  As 
shown  by  sections  and  by  pushing  a  wire  into  them  they  penetrate 
quite  deeply  into  the  mass  of  the  meteorite,  some  being  traceable 
an  inch  (2.5  cm.)  below  the  surface.  Their  extension  downward  is 
usually  in  a  slanting  direction  and  not  perpendicularly.  Sections  of 
the  meteorite  also  show  cracks  running  parallel  with  the  surface  at 
a  distance  of  about  one-half  inch  (1  cm.)  below  it,  and  others  extend 
inward  from  the  side  and  rear  of  the  meteorite.     The  prominent 


Oct.,  1907.       Meteoric  Studies  II  —  Farrington  117 

and  visible  cracks  are,  however,  all  on  the  front  side.  That  these 
cracks  are  due  to  the  necessity  of  a  contracted  exterior  adapting 
itself  to  a  larger  interior  there  can  be  no  doubt.  Whether,  however, 
their  origin  is  to  be  ascribed  to  heating  produced  by  the  passage  of  the 
meteorite  through  the  atmosphere  and  consequent  contraction  upon 
cooling,  or  to  slower  processes  of  weathering  after  its  fall  is  not  cer- 
tain. Shrinkage  cracks  observed  upon  meteorite  crusts  at  the  time  of 
fall  are  usually  of  a  finer  pattern  than  those  here  seen  and  penetrate 
little  below  the  crust.  The  rusted  character  of  the  interior  of  this 
meteorite  shows  that  it  has  long  been  exposed  to  the  weather.  The 
Dona  Inez  meteorite,  which  was  exposed  to  similar  climatic  condi- 
tions, is  described  by  Howell*  as  being  deeply  penetrated  by  cracks. 
The  writer  is  therefore  inclined  to  regard  the  cracks  in  this  meteorite 
as  due  to  a  slow  hydration  of  the  interior  of  the  meteorite,  such  as 
would  be  favored  by  an  arid  climate.  In  such  a  climate,  water  pene- 
trating into  the  interior  of  the  meteorite  through  minute  interstices 
would  be  held  and  cause  hydration,  while  from  the  exterior  it  would 
soon  dry  away.  Minute  cracks  would  thus  become  wedges  which 
would  gradually  split  the  meteorite  open.  The  crust  of  the  front  side 
while  in  general  smooth,  shows  irregular  patches  and  clots  of  fused 
matter  abundantly  distributed  over  it.  These  patches  are  in  general 
darker  than  the  surrounding  crust.  They  are  less  than  %  millimeter 
in  thickness  and  a  few  millimeters  broad.  They  grade,  however,  into 
grains  which  scattered  over  the  surface  produce  a  stippled  appear- 
ance. Drift  phenomena  are  lacking  except,  perhaps,  for  a  slight 
divergent  arrangement  of  grains  leading  out  from  one  or  two  of 
the  pits. 

The  rear  side  of  the  meteorite  as  received  showed  a  whitish'coating 
in  many  portions.  This  effervesces  and  can  be  removed  by  acid  and 
is  doubtless  a  carbonate  of  lime  similar  to  that  often  observed 
on  meteorites  which  have  been  exposed  for  some  length  of  time  in  arid 
regions.  When  this  coating  is  removed  the  true  crust  can  be  seen. 
This  is  in  part  black  and  in  part  red,  but  always  scoriaceous.  It  is 
probable  that  the  red  color  is  due  wholly  to  rusting  and  that  the  orig- 
inal crust  was  black.  The  texture  of  the  crust  as  seen  under  the  lens 
is  quite  uniform  and  minutely  cellular  throughout.  Minute  ridges 
and  hollows  and  partially  opened  blebs  indicate  fusion  with  the  pro- 
duction of  gas  bubbles.  This  crust  shows  a  tendency  to  flake  off  as  a 
unit  when  struck  with  a  hammer.  It  thus  has  the  characters  of  Bre- 
zina's  "bark  crust. "  The  pittings  of  this  surface  are  broad,  shallow, 
saucer-shaped  and  confluent.  Their  diameters  average  about  one 
♦Proc.  Rochester  Acad.  Sc,  1890,  Vol.  1,  p.  93. 


n8         Field  Columbian  Museum  —  Geology,  Vol.  III. 

inch  (2.5  cm.),  and  as  the  ridges  between  them  are  but  slightly  ele- 
vated they  give  the  surface  an  undulatory  character. 

The  surfaces  intermediate  between  front  and  rear  show  in  general 
transitional  crust  characters.  The  crust  is  more  uniform,  less  scaly 
and  thicker  than  on  the  front  side  and  less  scoriaceous  than  on  the 
rear.  The  edges  by  which  the  sides  join  the  front  and  rear  are  in  gen- 
eral rather  sharp  but  somewhat  rounded.  One  of  these  side  surfaces 
is  a  plane,  about  two  square  inches  (4  cm.)  in  area,  at  right  angles  to 
the  long  axis  of  the  meteorite.  The  clots  of  fused  matter  are  much 
thicker  and  narrower  on  this  face,  making  it  quite  rough.  Only  one 
other  broad  side  surface  occurs.  This  is  concave  and  has  a  smooth 
crust  more  nearly  like  that  of  the  front  side  but  thicker.  Those  sur- 
faces showing  no  primary  crust,  but  which  were  original  on  the  meteor- 
ite at  the  time  of  its  finding,  are  rough  from  fracture,  but  a  rounding 
off  of  the  protruding  grains  has  taken  place.  It  is  probable  that  the 
meteorite  broke  during  its  descent  to  the  earth  and  these  surfaces  were 
somewhat  glazed  over. 

The  interior  of  the  meteorite  presents  a  compact,  homogeneous 
appearance.  In  color  it  is  a  chocolate  to  reddish-brown,  thickly 
dotted  with  metallic  grains  which  show  upon  a  polished  surface.  It 
is  probable  that  the  present  color  is  largely  the  result  of  staining  from 
rust,  and  that  the  original  color  is  in  no  place  preserved.  The  metallic 
grains  are  quite  minute,  few  reaching  a  millimeter  in  any  dimension. 
They  appear  uniformly  but  not  very  abundantly  distributed.  To 
the  naked  eye  no  chondritic  structure  is  visible  either  upon  a  frac- 
tured or  polished  surface.  Under  a  lens,  however,  circular  spots  now 
dark  and  now  light,  but  for  the  most  part  darker  than  the  prevailing 
color  indicate  the  presence  of  chondri.  The  compact  appearance  of 
the  meteorite  likewise  disappears  under  a  lens.  The  whole  surface  of 
a  polished  mass  is  then  seen  to  be  thickly  sprinkled  over  with  minute, 
irregular  holes,  which  may  join  or  be  isolated.  These  cavities  may 
be  in  part  due  to  the  falling  out  of  grains,  in  the  process  of  polishing, 
but  as  their  borders  frequently  show  a  coating  of  limonite,  it  is 
probable  that  many  represent  an  original  cellular  structure,  or  are  due 
to  weathered-out  constituents. 

The  specific  gravity  of  the  meteorite,  obtained  by  weighing  a  piece 
of  557  grams,  was  found  to  be  3.4005. 

Crust  sections  are  of  interest  in  showing  a  structure  different  from 
that  usually  seen.  The  crust  microscopically  shows  two  well-marked 
zones.  The  outer,  .1  mm.  thick,  is  opaque  and  blebby.  The  inner, 
.3  mm.  thick,  has  a  microlitic  structure  with  occasional  rounded  crys- 
tals of  olivine.     It  is  semi-opaque,  presenting  a  gray  appearance  as 


Oct.,  1907.       Meteoric  Studies  II  —  Farringtox  119 

compared  with  the  dark-brown  to  black  of  the  outer  zone.  These 
microlites  have  an  elongated  form,  averaging  about  .02  mm.  in  length 
and  tend  to  a  fibrous  structure.  Succeeding  to  this  inner  zone,  while 
no  structural  change  is  apparent  as  compared  with  the  interior  of  the 
meteorite,  there  is  a  marked  series  of  cleavage  or  fracture  lines  running 
essentially  parallel  to  the  crust.  These  lines,  although  irregular  and 
frequently  anastomosing,  run  at  intervals  of  about  .05  mm.  The  zone' 
showing  these  lines  has  a  width  averaging  about  .2  mm. 

As  regards  the  remainder  of  the  section,  in  ordinary  light  a  field  of 
silicate  and  metallic  grains  is  presented,  with  the  siliceous  constituents 
exceeding  the  metallic.  There  is  considerable  limonitic  staining  of 
the  silicates  and  the  metallic  grains  are  for  the  most  part  bordered  by 
a  dark  zone  of  the  same  character.  Chondri  of  spheroidal  outline  oc- 
cur here  and  there,  but  are  not  abundant.  They  are  rather  uniform 
in  size.  Their  diameters  vary  from  .5  to  1  mm.,  being  generally  about 
.7  mm.  In  structure  they  present  chiefly  the  familiar  ribbed  and  por- 
phyritic  characters  produced  by  combinations  of  chrysolite  and  glass. 
The  general  form  of  the  chondri  is  spherical  but  many  are  plainly  frag- 
mental.  In  outline  the  chondri  are  rarely  sharply  separated  from  the 
adjoining  ground  mass,  althottgh  this  is  sometimes  the  case.  The 
ground  mass  of  the  meteorite  exclusive  of  the  chondri  is  made  up  of 
crystalline  fragments  varying  from  minute  grains  up  to  individuals 
.3-. 4  mm.  in  diameter.  Many  of  the  larger  individuals  show  crystal 
outlines  which  are  more  or  less  rounded.  High  interference  colors 
and  strong  double  refraction  show  these  to  be  chrysolite  for  the  most 
part.  The  larger  individuals  are  traversed  by  cleavage  cracks  along 
which  alteration  has  frequently  taken  place.  This  appears  in  the  form 
of  brownish  opaque  bands  which  suggest  iddingsite  traversing  the 
fragments.  Aside  from  these  the  crystals  are  free  from  clouding  or 
inclusions  for  the  most  part.  One  interesting  crystal,  however,  has  an 
outer  transparent  portion,  while  the  interior  shows  glass  and  skeleton 
growths.  The  metallic  grains  consist  of  nickel-iron  and  troilite, 
sometimes  singly  and  sometimes  in  combination.  They  have  irregu- 
lar branching  forms  and  seem  to  fill  the  interstices  between  the  silicate 
grains.  Their  form  shows  beyond  a  doubt  that  they  were  subsequent 
in  origin  to  the  silicates. 

MEJILLONES. 

Through  an  error  of  the  writer  in  copying  Wulfing's  classification, 
the  specimen  of  this  meteorite  in  the  Museum  collection  was  desig- 
nated *  as  a  brecciated  hexahedrite.  It  is  in  fact  an  iron-stone  meteor- 
*  Pubs.  Field  Col.  Mus.  1903.     Geol.  ser.  Vol.  II,  p.  107. 


120         Field  Columbian  Museum  —  Geology,  Vol.  III. 

ite  and  probably  a  mesosiderite.  The  error  of  notation  would  not 
have  been  significant  but  for  the  fact  that  the  accompanying  de- 
scription was  copied  by  Cohen*  in  his  account  of  the  brecciated  hexa- 
hedrites.  Under  the  name  of  Mejillones  two  masses  of  different  char- 
acters are  now  to  be  found  in  collections,  as  was  early  noted  by  Meu- 
nier.f  Meunier  recommended  the  name  of  Pseudomejillones  for  the 
iron-stone  fall.  As  such  a  nomenclature  would,  however,  not  be  in 
accordance  with  present  usage  it  would  seem  sufficient  to  designate 
one  as  Mejillones,  iron,  and  the  other  as  Mejillones,  iron-stone,  at  least 
until  some  further  information  can  be  obtained  regarding  the  origin 
of  the  masses.  It  is  not  impossible,  indeed,  that  they  may  be  parts  of 
the  same  mass  with  different  structures,  as  occurs  in  many  pallasites. 
Of  Mejillones,  iron,  but  a  small  quantity  seems  to  be  known.  Of  the 
specimens  listed  by  WulfingJ  under  this  name,  those  of  Harvard  and 
Ward  are  iron-stone.  The  Harvard  specimen  was  obtained  by  pur- 
chase from  Ward  and  Howell§,  as  was  also  the  specimen  in  this  Muse- 
um. Excluding  these  it  leaves  the  specimen  in  the  Paris  collection  as 
perhaps  the  only  well-authenticated  one  of  the  Mejillones  iron.  This 
specimen  according  to  Meunier  was  received  from  Domeyko. 

MODOC. 

This  meteorite  has  already  been  made  the  subject  of  a  brief  note!|  and 
detailed  study  ^f  by  Merrill  and  a  note  by  the  present  writer.**  Some 
additional  facts  obtained  by  the  writer  during  a  visit  to  the  locality  in 
February,  1906,  and  by  study  of  specimens  seem  worthy  of  record. 
These  observations  include  accounts  of  the  phenomena  of  fall  obtained 
from  various  residents  of  Modoc,  also  at  Tribune,  forty  miles  west  of 
Modoc.  The  accounts  at  the  latter  place  show  a  much  shorter  interval 
to  have  intervened  between  light  and  sound  than  at  Modoc.  This 
seems  conclusive  evidence  that  the  meteor  exploded  over  Tribune  and 
traveled  about  forty  miles  before  falling.  The  accounts  here  given 
are  arranged  in  the  order  of  the  position  of  the  observers  going  east- 
ward. 

Mr.  Raines,  the  station  agent  at  Tribune,  was  about  to  lower  a  cur- 
tain at  an  east  window  when  he  saw  the  meteor  at  the  north  going 

*  Meteoritenkunde,  Heft  III,  p.  233. 

f  1893.     Revision  des  fers  meteoriques,  p.  75. 

X  Die  Meteoriten  in  Sammlungen,  p.  230. 

§  Huntington,  Catalogue  of  all  recorded  meteorites,  1887,  p.  93. 

||  Science  1906,  N.  S.  XXIII,  p.  391. 

T|  Am.  Jour.  Sci.  1906,  (4):  21,  pp.  356-360. 

**  Science  1906,  N.  S.  XXIII,  p.  582. 


Oct.,  1907.        Meteoric  Studies  II  —  Farrixgton  121 

«• 
eastward.  Its  appearance  was  that  of  a"  ball  of  fire,  resembling  an 
electric  light  in  color  and  of  the  size  of  a  "wash  tub."  In  a  short  space 
of  time,  probably  two  or  three  seconds,  it  exploded,  throwing  but 
sparks  and  then  disappeared,  leaving  no  trail  behind  it.  In  about  30 
seconds  three  muffled  reports  and  a  continuous  roar  like  thunder  were 
heard. 

Mr.  P.  W.  Grimes,  of  Tribune,  was  sitting  with  his  head  down,  fac- 
ing west,  when  a  light  like  that  of  an  electric  light  attracted  his  atten- 
tion. He  saw  a  ball  of  fire  to  the  north,  traveling  east.  The  light 
lasted  two  or  three  seconds  and  in  about  20  seconds  came  three  muf- 
fled reports  like  those  of  thunder. 

Mr.  Willie  Baugh  was  driving  south  about  two  miles  from  Modoc. 
He  saw  a  light  to  the  west,  resembling  an  electric  light,  seemingly  fall- 
ing towards  him.  Then  it  seemed  to  describe  an  upward  path  and 
exploded,  sparks  going  in  different  directions  like  those  of  a  Roman 
candle. 

Mr.  and  Mrs.  W.  E.  Curtis,  of  Modoc,  had  retired  for  the  night  when 
Mrs.  Curtis  was  awakened  by  a  light  so  bright  that  she  thought  the 
barn  was  afire.  This  light  was  followed  by  three  reports  like  thunder 
and  a  sound  like  the  wind  coming  up.  She  awakened  Mr.  Curtis,  who 
went  to  the  porch,  and  then  heard  sounds  like  hailstones  falling.  The 
fall  of  each  stone  was  accompanied  by  slight  hissing  sounds.  Next 
morning  Mr.  Curtis  found  a  stone  weighing  about  one  pound  in  his 
yard,  and  others  later. 

Mr.  and  Mrs.  Fred  Yost,  living  only  a  few  rods  from  Mr.  Curtis 
heard  a  sound  like  accentuated  thunder,  but  saw  no  light  nor  heard 
any  stones  falling.  They  found  several  stones  about  their  premises 
later. 

Mr.  Schirmeyer,  of  Modoc,  was  in  doors.  He  saw  a  light  at  an  east 
window  and  stepped  out  on  the  porch  to  examine  it.  Two  or  three  ex- 
plosions like  rifle  shots  followed,  also  swishing  sounds  like  the  dropping 
of  stones.  Rumbling  sounds  then  died  away  to  the  west  for  about 
five  minutes. 

Mr.  Irwin,  of  Modoc,  saw  a  light  below  a  partially  lowered  curtain. 
He  called  to  his  wife  to  see  what  was  going  on.  She  got  up  for  a  mo- 
ment and  then  retired  again;  and  then  came  sounds  which  led  them 
to  think  that  a  smashup  had  occurred  on  the  railroad  near  by. 

Mr.  T.  D.Marshall  was  coming  up  out  of  his  cellar  at  the  time  of  the 
fall.  His  attention  was  attracted  by  a  bright  light  in  the  sky,  which 
was  followed  by  a  sound  like  four  beats  on  a  bass  drum  and  others  like 
the  swish  which  accompanies  the  shooting  of  a  rocket.  He  then  heard 
stones  striking  in  a  number  of  places  about  his  house.     He  expected  to 


122  Field  Columbian  Museum  —  Geology,  Vol.  III. 

« 
be  able  to  find  a  number  of  these  the  next  morning,  but  on  searching 
succeeded  in  discovering  only  one. 

Mr.  McDonald  heard  sounds  like  the  firing  of  a  machine  gun,  and  a 
few  days  later  found  a  small  stone  about  ioo  feet  from  his  house. 

Mr.  J.  K.  Freed  heard  sounds  like  those  of  a  machine  gun. 

Inhabitants  of  Scott,  about  four  miles  east  of  the  place  of  fall,  gen- 
erally described  the  sounds  as  like  those  of  a  wagon  traveling  over  a 
bridge. 

An  account  of  the  occurrence  published  in  the  local  paper,  the 
Scott  County  Chronicle,  Sept.  8,  1905,  six  days  after  the  fall,  was  as 
follows : 

"  Last  .Saturday  night  about  10  o'clock  a  remarkably  bright  meteor 
was  seen  in  the  heavens  west  from  this  city.  It  was  almost  as  light  as 
day.  The  explosion  occurred  in  the  vicinity  of  Modoc  and  was  heard 
clear  across  the  county.  T.  D.  Marshall  had  a  piece  of  the  meteor  in 
town  Wednesday  which  he  found  near  his  house,  which  is  black  on  the 
outside  and  gray  on  the  inside,  and  is  heavily  charged  with  metal 
indicating  silver  and  gold.  It  is  reported  that  W.  E.  Curtis  and  a 
man  named  Pence  have  found  pieces  that  show  that  the  remnants 
were  scattered  over  several  miles  of  territory.  Mr.  Marshall  says 
the  commotion  in  his  territory  was  simply  terrifying." 

Under  Modoc  items  an  account  was  given  in  the  same  paper  as  fol- 
lows : 

"Last  Saturday  night  about  9  o'clock  a  meteor  passed  over  this 
locality.  It  was  followed  by  a  roar  that  sounded  like  thunder.  It 
probably  bursted,  as  fragments  were  heard  falling  by  several  persons 
and  T.  D.  Marshall  and  W.  E.  Curtis  each  found  one.  The  parts  found 
were  dark  lead  color,  almost  black,  and  give  a  metallic  sound  when 
struck.  They  are  checked  by  small  cracks  indicating  an  extremely 
heated  condition  while  passing 'through  the  air.  They  weigh  but  a 
few  ounces,  yet  are  prized  by  the  finders  as  they  probably  represent 
part  of  some  planet  far  away,  and  have  traveled  for  millions  of  miles 
through  space  before  finding  a  resting  place  on  Earth." 

The  difference  in  time  of  these  two  accounts  is  accounted  for  by  the 
fact  that  in  Modoc,  Mountain  time  is  used,  but  in  Scott,  Central  time. 

The  area  over  which  the  meteoric  stones  were  found  was  one  about 
seven  miles  by  two,  the  longer  distance  extending  east  and  west.  The 
region  is  a  rolling  prairie,  rather  thinly  inhabited.  Much  of  the  area  has 
never  been  plowed.  The  native  sod,  or  "buffalo  sod,"  as  it  is  often 
called,  proved  comparatively  impenetrable  to  the  stones  which  fell 
upon  it.  A  slight  indentation  in  the  sod  showed  plainly  where  a  stone 
weighing  7  pounds,  found  by  the  writer,  had  struck.     The  ground  also 


Oct.,  1907.       Meteorite  Studies  II  —  Farrixgtox  123 

was  bare  at  that  point,  showing  that  the  grass  had  been  killed.  The 
meteorite  did  not  lie  at  the  point  where  it  had  struck,  however,  but 
about  its  own  width  (four  inches)  to  the  south.  It  had  thus  evidently 
bounced  southward  on  striking.  Mr.  McDonald,  of  Modoc,  informed 
the  writer  that  the  stone  which  he  found  had  also  bounded  southward. 
Mr.  Freed,  of  Modoc,  informed  the  writer  that  the  stone  which  he  found 
had  penetrated  the  sod  about  four  inches.  This  was  of  tabular  form 
and  was  on  edge.     It  weighed  11  lbs. 

The  following  list  shows  the  individual  stones  which  had  been 
found  at  the  time  of  the  writer's  visit  and  the  names  of  the  finders. 
All  of  these  masses  were  seen  by  the  writer.  The  weights  are  in  sev- 
eral cases  approximate  only.  Those  that  are  known  accurately  are 
given  in  grams. 

Weight.  Finder. 

1.  io}4  lbs.  (4,640  grams) .J.  K.  Freed. 

2.  7    lbs.  (3,171  grams) O.  C.  Farrington. 

3.  5    lbs. F.  P.  Heller. 

4.  2  lbs.  10  oz.  (1,170  grams) F.  P.  Heller. 

5.  ilb.    15  oz.  (    879  grams) F.  P.  Heller. 

6.  1  lb.      6  oz.  (    624  grams) John  March. 

7.  1  lb.      1  oz.  (    490  grams) Fred  Yost. 

8.  14    oz.  — McDonald. 

9.  12K0Z.  W.E.Curtis. 

10.  10    oz.  T.  D.  Marshall. 

11.  6    oz.  Fred  Yost. 

12.  6    oz.  (170  grams) Fred  Yost. 

13.  6    oz.  Mrs.  W.  E.  Curtis. 

In  addition  the  find  of  an  individual  weighing  1  y2  lbs.  was  reported 
by  O.  L.  Douglass,  and  of  one  weighing  2  lbs.  by  F.  P.  Heller.  Thus  a 
total  of  at  least  fifteen  stones  has  been  found,  having  an  aggregate 
weight  of  about  35  lbs.  (16  kgs.). 

The  distribution  of  these  specimens  over  the  area  in  falling  shows  a 
remarkable  gradation  in  accordance  with  their  size.  The  stones  fell 
in  order  of  their  weight  from  west  to  east.  This  is  graphically  shown 
in  Plate  XXXVII.  The  two  individuals  weighing  1  lb.  and  2  lbs.  each 
found  in  the  vicinity  of  the  5  lb.  mass  are  fragments,  the  remaining 
portions  of  which  were  not  found  although  extended  search  was  made, 
and  the  region  is  exceptionally  favorable  for  searching  for  meteorites. 
The  smooth  buffalo  sod  has  no  other  stones  upon  it  and  the  vegetable 
growth  is  not  sufficient  to  hide  stones  of  appreciable  size.  These  frag- 
mentary individuals  are  shown  in  Plate  XL.  The  complete  indi- 
viduals would  probably  weigh  about  5  lbs.  each.  Some  of  the  non- 
crusted  surfaces  of  these  show"  blackening  while  others  are  perfectly 


124         Field  Columbian  Museum  —  Geology,  Vol.  III. 

fresh.  The  completely  encrusted  individuals  are  of  irregular,  angular 
shapes,  with  angles  slightly  rounded,  as  is  usual  in  meteorites.  Sev- 
eral, however,  show  projecting  spurs  of  toothed  form  which  are  unus- 
ual. No.  10,  Plate  XXXIX,  is  especially  notable  for  these.  The 
three  views  given  of  this  individual  show  its  orientation.  The  broad 
surface  with  rounded  shallow  pits  was  the  rear  side,  the  opposite  the 
front  side.  As  shown  by  the  side  view,  the  individual  is  fragmentary. 
The  individual  found  by  the  writer,  shown  in  Plate  XXXVIII,  has 
a  roughly  tetrahedral  form  with  one  of  the  faces  of  the  tetrahedron 
broken  up  into  three  planes.  The  faces  are  nearly  all  slightly  concave 
and  show  only  a  few  broad  pittings.  A  marked  feature  of  the  surface 
is  a  whitish  deposit  occurring  on  several  of  the  faces.  This  deposit  is 
more  or  less  streaked  in  appearance  and  the  direction  of  the  streaks  is 
such  that  they  would  meet  in  a  common  point  if  produced.  Exam- 
ined under  a  lens  the  deposit  is  seen  to  be  a  fine  powder  embedded  in 
the  interstices  of  the  slaggy  crust.  It  is  soluble  without  effervescence 
in  hydrochloric  acid  but  is  so  small  in  quantity  that  further  determina- 
tion of  its  nature  cannot  be  made.  The  simplest  explanation  of  its 
origin  would  seem  to  be  to  regard  it  an  efflorescence  due  to  weathering, 
as  the  meteorite  had  been  exposed  five  months  to  the  elements  when 
found.  The  uniformity  of  direction  of  the  streaks  is  somewhat  diffi- 
cult to  account  for  on  this  hypothesis,  however.  One  of  the  upper- 
most faces,  moreover,  is  entirely  free  from  the  deposit.  The  deposit 
lies  on  what  was  undoubtedly  the  forward  portion  of  the  meteorite  in 
falling  and  the  radiation  of  the  streaks  from  a  common  point  suggests 
that  it  was  made  during  flight.  In  either  case  the  phenomenon  is  new 
to  the  writer's  experience.  The  individuals  shown  in  Plate  XL  were, 
as  already  stated,  fragments  when  found,  and  no  adjoining  parts  have 
yet  been  discovered  in  the  vicinity  so  far  as  the  writer  is  aware.  The 
encrusted  portion  of  one  is  seen  to  be  deeply  pitted,  the  pits  varying 
in  form  and  size  on  the  different  surfaces.  On  one  surface  they  are 
abundant,  small  and  uniformly  distributed,  on  others  fewer  in  number, 
larger  and  deeper.  The  complete  individual  was  evidently  of  tabular 
form  and  about  2  inches  (5  cm.)  thick.  One  of  the  broad  surfaces  is 
remarkably  flat  and  shows  well-marked  divergent  lines  of  flow  on  the 
crust.  The  other  individual  shown  in  this  plate  illustrates  the 
internal  veins  which  occur  in  some  specimens.  These  veins  are 
evidently  only  armor  faces  produced  by  slipping.  They  are  planoid 
in  character  and  run  in  various  directions  which  often  intersect. 
The  crust  of  most  of  the  individuals  is  dull  and  coal-black  in  color, 
though  of  reddish  tone  in  some  individuals.  Crackling  of  the  crust 
into  irregular  polygonal  areas  is  a  common  and  characteristic  feature, 


Oct.,  1907.       Meteorite  Studies  II  —  Farrington  125 

as  shown  in  several  of  the  plates.  The  crackle  lias  a  mesh-like 
pattern  with  meshes  in  the  form  of  polygons,  squares  and  triangles 
from  Y  to  yi  inch  on  a  side.  The  appearance  is  entirely  similar 
to  that  presented  by  crackled  earthen  ware  and  is  doubtless  produced 
by  shrinking  of  the  crust  in  cooling,  or  expansion  of  the  interior  of  the 
meteorite  subsequent  to  the  formation  of  the  crust.  Another  interest- 
ing feature  seen  on  the  crust  of  several  individuals  is  that  of  glazed 
spots  of  occasional  occurrence.  The  spots  are  usually  of  a  greenish 
color,  oval  to  circular  in  area,  and  vary  from  Y  ^°  H  mcn  m  diameter. 
They  doubtless  mark  the  location  of  chondri  of  fusible  composition. 
Under  the  microscope  the  crust  shows  in  cross  section  a  thickness 
of  about  .5  of  a  millimeter.  The  three  zones  of  Tschermak  are  plainly 
marked,  with  widths  averaging  as  follows:  Fusion  zone  .025  mm., 
absorption  zone  .1  mm.,  impregnation  zone  .4  mm.  These  zones  ex- 
hibit the  usual  characters,  the  fusion  zone  being  black,  opaque  and 
glassy,  the  absorption  zone  transparent,  and  the  impregnation  zone 
showing  a  large  proportion  of  black,  opaque  matter.  The  relative 
widths  above  given  remain  fairly  constant,  although  in  places  the  ab- 
sorption and  fusion  zones  are  of  about  equal  width,  and  again  the 
absorption  zone  may  disappear  altogether.  The  fusion  zone  is  at 
times  also  blebby  and  rough  in  outline.  The  interior  of  the  meteorite 
is  megascopically  ash-gray  in  color,  in  some  individuals  flecked  with 
rusty  spots.     The  substance  is  only  fairly  coherent,  and  will  not  polish. 

PONCA  CREEK. 

The  writer  proposes  the  name  of  Ponca  Creek  for  the  meteorite  usu- 
ally known  as  Dakota.  The  reasons  for  the  change  are  as  follows: 
The  original  account  by  Jackson*  states  that  the  fragment  which  he 
described  was  given  him  by  the  U.  S.  Indian  agent  for  the  Ponca  tribe 
of  Indians,  and  further  that  the  mass  was  found  on  the  surface  of  the 
ground  "in  the  Dakota  Indian  territory,  ninety  miles  from  any  road  or 
dwelling."  In  the  repetition  of  this  statement  by  foreign  authorities 
a  comma  came  to  be  inserted  after  Dakota,  so  that  the  locality  was 
known  as  Dakota,  Indian  Territory.  There  is  no  such  locality,  how- 
ever, and  Indian  Territory  is  several  hundred  miles  removed  from  the 
place  where  the  meteorite  was  found.  Moreover,  the  original  territory 
of  Dakota,  within  which  the  meteorite  may  have  been  found,  is  now 
subdivided  into  North  and  South  Dakota  and  neither  name  would  desig- 
nate the  locality  in  a  sufficiently  limited  way.  The  reservation  of  the 
Ponca  Indians,  who  were  a  tribe  of  the  Dakotas  and  from  whose  agent 
•Am.  Jour.  Sci.  (2)  36,  pp.  259-261. 


126  Field  Columbian  Museum  —  Geology,  Vol.  III. 

the  meteorite  was  obtained  by  Jackson,  was  at  that  time  located  along 
Ponca  Creek  in  Nebraska.  It  seems  reasonable  to  suppose  that  the 
meteorite  was  found  in  the  vicinity  of  this  creek,  and  the  name  Ponca 
Creek  has  the  additional  advantage  of  containing  that  of  the  tribe  by 
some  member  of  which  the  meteorite  was  probably  originally  found. 
For  the  meaningless  name  Dakota,  therefore,  that  of  Ponca  Creek 
may  well,  in  the  opinion  of  the  writer,  be  substituted. 

SALINE. 

Some  further  observations  may  here  be  added  to  the  brief  account 
of  this  meteorite  given  by  the  writer  in  1902.*  The  approximate 
place  of  find  of  the  meteorite  was  kindly  indicated  to  the  writer  by  Mr. 
S.  A.  Sutton,  and  this  is  shown  in  Plate  XLI.  No  other  observations 
of  the  fall  than  those  already  made  by  Mr.  Sutton  and  reported  byvthe 
writer  seem  to  be  known.  The  shape  of  the  meteorite  may  be  de- 
scribed as  approximately  that  of  a  truncated,  four-sided  pyramid. 
The  base  of  the  pyramid,  shown  in  Plate  XL  1 1,  was  plainly  the  rear  side 
of  the  meteorite  in  falling.  It  is  the  broadest  surface  of  the  mass,  and 
has  an  area  of  about  144  square  inches  (900  sq.  cm.).  In  outline  it  is 
roughly  circular.  Mr.  Sutton  states  that  this  was  the  surface  on  which 
the  meteorite  rested  when  found,  but  this  position  could  have  been 
brought  about  by  an  overturn  when  striking.  It  was  more  heavily 
coated  with  carbonate  of  lime  when  received  at  the  Museum  than  any 
of  the  other  surfaces.  It  is  nearly  flat,  though  slightly  concave,  and 
shows  the  broad,  shallow  pits  characteristic  of  these  surfaces  of  meteor- 
ites. On  the  opposite  side  of  the  meteorite  a  surface  having  the  form 
of  a  long  and  narrow  isosceles  triangle  runs  nearly  parallel  to  it  and 
the  thickness  of  the  meteorite  between  the  two  surfaces  ranges  from 
7  to  8  inches  (18  to  20  centimeters).  From  the  parallel  surface  the 
meteorite  slopes  away  at  angles  of  400,  500,  6o°  and  900  approximately. 
Three  of  these  surfaces  are  approximately  plane,  the  others  are 
rounded.  A  view  of  the  meteorite  showing  this  feature  is  given  in 
Plate  XLI  I.  Views  of  the  mass  from  two  other  sides  were  published 
in  the  Catalogue  of  Meteorites  of  the  Museum. f  The  plane  surfaces 
show  practically  no  pits,  the  others  are  more  or  less  irregularly  pitted. 
The  more  symmetrical  of  these  pits  are  oval  in  form,  from  yi  to  ^ 
inches  in  their  longest  diameter  and  have  a  depth  about  one-fourth  as 
great.  All  the  edges  produced  by  the  meeting  of  different  surfaces  of 
the  meteorite  are  rounded. 

*  Science,  N.  S.  Vol.  XVI,  pp.  67,  68. 

t  Pubs.  Field  Col.  Mus.   1903,  Geol.  ser.  Vol.  II,  Plate  XXX. 


Oct.,   1907.        Mkikorite  Studies  II  —  Parking r<>\  127 

Except  where  it  lias  scaled  off  in  small  areas  the  meteorite  is  cov- 
ered with  a  firmly  adherent,  dull  brown-black  crust,  rough  from  the 
protrusion  of  thickly  scattered  metallic  grains.  These  grains  are 
darker  in  color  than  the  rest  of  the  crust,  probably  from  a  coating  of 
iron  oxide.  When  this  coating  is  scraped  away,  however,  the  bright 
nickel-white  color  of  the  metallic  grains  is  seen.  One  of  the  grains 
showed  bright  when  the  meteorite  was  received,  but  it  may  perhaps 
have  become  so  through  handling.  It  is  the  largest  single  grain  to  be 
seen.  It  has  a  hemispherical  form  and  a  diameter  of  5  mm.  The  shapes 
of  the  other  metallic  grains  as  they  protrude  are  various.  Some  are 
elongated,  some  nearly  circular  and  others  form  small  connecting 
groups.  For  the  most  part  the  grains  are  independent  of  each  other, 
but  there  are  two  well-defined' groups  of  them  extending  in  irregular 
lines  and  standing  out  like  veins.  These  are  not  straight  in  their 
course  but  nearly  so.  The  extent  of  each  is  about  6  cm.  (2^  inches). 
One  runs  from  the  large  grain  mentioned  above,  the  other  is  nearlv 
parallel  to  it  7  inches  (18  cm.)  distant. 

Besides  being  broken  by  the  protrusion  of  the  metallic  grains,  the 
crust  is  seamed  and  fissured  by  numerous  cracks  extending  in  all  direc- 
tions and  varying  in  extent  and  depth.  The  largest  has  a  length  of  6 
inches  (15  cm.),  and  from  this  to  the  minutest  fissures  all  gradations 
occur.  The  course  of  most  of  the  cracks  is  straight  towards  the  inte- 
rior of  the  meteorite,  but  some  run  so  as  to  tend  to  scale  off.  They 
give  the  exterior  of  the  meteorite  a  "baked"  look  and  there  can  he 
little  doubt  that  they  are  the  result  of  differential  expansion  through 
heat  of  the  interior  as  compared  with  the  exterior.  Scaling  of  the  crust 
had  occurred  at  various  points  when  the  mass  reached  the  Museum. 
Many  of  these  scalings  must,  on  account  of  their  freshness,  have 
occurred  very  shortly  before  the  meteorite  struck  the  earth  or  from  the 
force  of  impact.  Most  of  the  surfaces  thus  exposed  were  covered  with 
an  adherent  coating  of  carbonate  of  lime  when  the  stone  was  received 
at  the  Museum.  The  lime  undoubtedly  deposited  more  readily  here 
on  account  of  the  increased  capillary  attraction  afforded  by  such  sur- 
faces. The  color  of  these  surfaces  was  for  the  most  part  rusty  brown 
from  exposure,  but  a  few  were  of  a  greenish -gray  color  where  "the  car- 
bonate of  lime  was  freshly  removed.  In  addition  to  these  wholly  1111- 
crusted  surfaces  one  about  three  inches  square  had  a  very  thin  black 
crust,  much  thinner  than  the  average  crust.  It  is  evident  that  at  this 
point  a  piece  scaled  off  from  the  meteorite  during  its  passage  through 
the  air  and  time  sufficed  for  Only  a  partial  fusing  of  the  freshly  exposed 
surface. 

Internally  the  substance  of  the  meteorite  when  freshly  broken  is 


128         Field  Columbian  Museum  — -Geology,  Vol.  III. 

■  of  a  greenish-gray  color  and  firmly  coherent  texture  so  that  it  takes  a 
good  polish.  Enough  weathering  has  taken  place,  however,  to  give 
the  interior  in  large  part  a  dark-brown  color.  The  percentage  of 
metallic  grains  seen  on  a  polished  surface  is  large,  so  as  to  seemingly 
constitute  about  one-fourth  the  mass.  The  metal  is  uniformly  dis- 
tributed but  the  grains  vary  in  size  and  shape.  Some  having  a  diameter 
of  4-5  mm.  are  discernible.  At  times  they  aggregate  into  vein-like  lines. 
Both  polished  and  unpolished  sections  show  the  interior  of  the  meteor- 
ite to  be  penetrated  by  a  great  number  of  minute  fissures  arising  prob- 
ably from  hydration.  Most  of  them  contain  carbonate  of  lime  which 
has  doubtless  been  brought  in  by  infiltrating  waters.  Such  fissures, 
as  well  as  the  metallic  "veins"  are  shown  in  an  illustration  published 
in  the  Museum  Catalogue  of  Meteorites  of  1903.*  Under  the  micro- 
scope all  the  striking  characters  of  the  spherical  chondrites  are  pre- 
sented by  the  meteorite.  Chondri  of  great  variety  of  size  and  struc- 
ture make  up  the  principal  mass.  For  the  most  part  the  chondri  are 
spherical  in  form  but  some  are  oval  and  others  of  unsymmetrical  out- 
line. Besides  complete  chondri,  fragments  of  chondri  are  to  be  seen. 
As  was  stated  in  the  writer's  first  paper  on  the  meteorite,  enstatite  and 
olivine  either  singly  or  in  combination  chiefly  compose  the  chondri. 
Diameters  of  from  .3 -.6  mm.  are  presented  as  a  rule  by  the  enstatite 
chondri,  but  one  3  mm.  in  diameter  was  seen  in  one  section.  Several 
of  the  half-glassy  chondri  show  rounded  depressions  as  if  made  by 
the  pressure  of  another  chondrus.  The  olivine  chondri  are  both  mono- 
somatic  and  poly  somatic,  also  porphyritic  and  lamellar.  In  dimen- 
tion  they  vary  as  widely  as  do  the  enstatite  chondri  and  between  about 
she  same  limits.  The  porphyritic  individuals  of  the  chondri  show, 
as  a  rule,  well-marked  prismatic  outlines.  Crust  sections  under  the 
microscope  fail  to  show,  except  for  an  outer  fusion  zone,  well  marked 
zones  such  as  are  common  in  the  more  porous  chondrites.  The  fusion 
zone  is  of  a  dark,  nearly  opaque,  somewhat  blebby  and  glassy  nature 
and  has  a  thickness  of  about  .08  mm.  Succeeding  this,  towards  the 
interior  of  the  meteorite,  a  zone  about  .4  mm.  in  thickness  shows  scat- 
tered opaque  impregnations  interspersed  among  unaltered  olivine 
crystals.  This  zone  is  not  uniform  in  occurrence,  however,  and  can 
be  seen  only  at  intervals. 

WHSTON. 

In  connection  with  the  meteorite  fall  which  occurred  at  Weston, 
Connecticut,  December  14,   1807,  a  well-marked  distribution  of  the 
masses  according  to  weight  took  place  to  which  attention  does  not 
*  Pubs.  Field  Col.  Mus.  Geol.  ser.  Vol.  II,  PI.  XXXI. 


Oct.,   1907.        Meteorite  Studies  II — Farringtox  129 

seem  to  have  been  called  in  detail  hitherto.  In  Silliman  and  Kings- 
ley's  account*  the  fact  is  noted  that  stones  fell  from  the  meteorite  at 
six  different  places,  over  an  area  9  to  10  miles  in  length.  It  is  stated 
by  these  authors  that  these  masses  fell  in  a  line  differing  little  from  the 
course  of  the  meteor,  and  probably  in  the  order  of  the  most  northerly 
first  and  the  most  southerly  last.  The  relation  of  the  weight  of  the 
masses  to  this  order  was  not  traced  by  these  authors,  however.  This 
relation  as  shown  by  the  subsequent  account  is  as  follows : — The  most 
northerly  fall  (near  Mr.  Burr's)  broke  into  fragments  from  striking  a 
rock  of  granite.  Its  estimated  weight  was  20-25  pounds.  The  next 
fall  was  at  Mr.  Prince's,  five  miles  south  from  Mr.  Burr's.  This  stone 
weighed  36^  lbs.  About  half  a  mile  northwest  of  this,  however,  one 
was  found  weighing  7-10  lbs.  and  half  a  mile  northeast  one  weighing 
13  lbs.  These  two  masses  were  doubtless  related  to  the  36  lb.  mass. 
The  next  mass  in  a  southerly  direction  was  found  two  miles  southeast 
of  Mr.  Prince's  at  Mr.  Porter's.  This  was  also  broken  but  is  regarded 
as  having  weighed  from  20  to  25  lbs.  and  was  probably  also  related  to 
the  36  lb.  mass.  The  largest  mass  of  all  fell  near  Mr.  Elijah  Seely's, 
about  four  miles  from  Mr.  Prince's.  The  direction  of  this  locality  from 
the  others  is  not  stated,  but  from  the  context  there  can  be  little  doubt 
that  it  was  south.  This  mass  weighed  about  200  lbs.  The  distribu- 
tion of  the  masses  thus  shows  a  distinct  arrangement  according  to 
weight  and  direction.  As  Bowditchf  determined  by  an  independent 
investigation  that  the  course  of  the  meteor  was  South  70  West,  it  is 
evident  that  the  smaller  stones  fell  first.  The  distribution  of  the 
masses,  as  above  noted,  also  accords  with  the  statements  of  several 
witnesses  at  the  time  that  the  sound  of  three  separate  explosions  ac- 
companied the  passage  of  the  meteor.  The  smaller  masses  near  Mr. 
Prince's  were  evidently  thrown  off  at  the  time  of  the  second  explosion. 

*  Trans.  Amer.  Philos.  Soc.  Phila.  Vol.  6,  i8oq,  pp.  323,  325,  335-345. 
f  Mem.  Acad.  Arts  and  Sci.  1815  Vol.  3,  pp.  213-236. 


LIBKAKY 

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URBANA 


FIELD  COLUMBIAN  MUSEUM. 


GEOLOGY,  VOL.  Ill,  PLATE  XXIX. 


Front  and  Side  Views  of  Small  Bath  Furnace  Meteorite,    x  14. 


LIBRARY 

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URBANA 


FIELD  COLUMBIAN  MUSEUM. 


GEOLOGY,  VOL.  Ill,  PLATE  XXX. 


Place  of  Fall  of  the  178-lb.  Bath  Furnace  Meteorite. 


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D 


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GEOLOGY,  VOL.  Ill,  PLATE  XXXV. 


Rear,  Side  and  Front  Views  of  Cast  of  Iron  Creek  Meteorite,    x  i. 


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UNlVbRSI  l Y  0*  ILLINOIS 

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Front  and  Rear  Views  of  7-lb  Modoc  Meteorite,    x  It, 


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Fragmentary  Individuals  of  Modoc  Meteorite.    Nos.  5  and  6  of  List,    x  }?. 


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UMVtRSIIY  OF  ILLINOIS 

URBANA 


FIELD  COLUMBIAN   MUSEUM. 


GEOLOGY,  VOL.  Ill,  PLATE  XLII. 


Front  and  Rear  Views  of  Saline  Meteorite,    x  J. 


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Mr.  Burr's 


20  lbs. 


Mr.  Prince's 
7-10  lbs.  #  %    13  lbs. 

36£  lbs. 


Mr.  Porter's 
20=25  lbs. 


Mr.  Seely's 


200  lbs. 

Diagram  Showing  Distribution  of  Individuals  of  Weston  Meteorite.    The  Length 
of  the  Area  Included  is  Nine  Miles. 


UNIVfcKSIIY  01-  ILLINOIS 
URBANA 


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